Sara Bareilles leaving 'The Sing-Off' -- EXCLUSIVE

The X Factor and The Voice aren’t the only singing shows shaking up their judging panels this year.

Sara Bareilles is leaving NBC’s competition series The Sing-Off. The Grammy-nominated singer-songwriter wants to “focus on her music,” says a source close to Bareilles. She replaced original Sing-Off judge Nicole Scherzinger for the show’s third season after Scherzinger departed to Fox’s X Factor.

The move creates at least one opening on the judges panel for the lively a cappella competition. The show is being overhauled for its upcoming fourth round by its new executive producer – The Voice and Survivor guru Mark Burnett. It’s not yet clear if there are more departures to come. The show stars host Nick Lachey, and judges Ben Folds and Shawn Stockman.

Since The Sing-Off premiered in December, 2009, the series has its ups and downs in the ratings, but has maintained a fan-base of admirers. When it wasn’t renewed in 2012, many thought the show was cancelled. But last month NBC announced The Sing-Off would return sometime during the holiday season.

“The Sing-Off showcases great talent and a musical form I love,” Burnett said last month. “It’s very special, and we’re excited to be involved.”